Search results for "45"
showing 10 items of 1896 documents
Stable expression of rat cytochrome P-450IIB1 cDNA in Chinese hamster cells (V79) and metabolic activation of aflatoxin B1.
1988
V79 Chinese hamster fibroblasts are widely used for mutagenicity testing but have the serious limitation that they do not express cytochromes P-450, which are needed for the activation of many promutagens to mutagenic metabolites. A full-length cDNA clone encoding the monooxygenase cytochrome P-450IIB1 under control of the simian virus 40 early promoter was constructed and cointroduced with the selection marker neomycin phosphotransferase (conferring resistance to G418) into V79 Chinese hamster cells. G418-resistant cells were selected, established as cell lines, and tested for cytochrome P-450IIB1 expression and enzymatic activity. Two cell lines (SD1 and SD3) were found that stably produc…
Dominant contribution of P450 3A4 to the hepatic carcinogenic activation of aflatoxin B1.
2006
The hepatic carcinogen aflatoxin B1 (AFB1) is metabolized in the liver by at least four different P450s, all of which exhibit large interindividual differences in the expression levels. These differences could affect the individual risk of hepatocellular carcinoma (HCC). We investigated the metabolism of AFB1 in a panel of 13 human liver microsomal preparations using a hepatic abundance model, which takes into account the specific kinetic parameters and the expression levels of these P450s. We found a 12-fold variability in the production rate of the carcinogenic metabolite AFB1-8,9-epoxide (AFBO) and a 22-fold variability in the production of the detoxification product AFQ1. The ratio betw…
Microbial safety of black summer truffle collected from Sicily and Umbria Regions, Italy
2021
Background: Tuber aestivum Vittad., known as black summer truffle, represents high-value food especially used as garnishment in nouvelle cuisine. The aim of this study was to investigate on the viable microbial populations associated with T. aestivum ascomata collected in different sites of Sicily and one locality of Umbria (Italy).
 Methods: The ripe ascomata of black summer truffles were collected from Central Italy. Cell densities of spoilage bacteria, fecal indicators, potential pathogens, yeasts, and molds were analyzed. Statistical analysis was conducted with XLSTAT software.
 Results: The microbiological counts of truffles ranged between 6.00 and 9.63 log Colony Forming Uni…
Moving European research on work and ageing forward: Overview and agenda:
2010
This paper summarizes the state of affairs of European research on ageing and work. After a close inspection of the age construct, an overview is presented of research in four areas: the relationship between age and HR-policies, early retirement, age and performance/employability, age and health/well-being. The overview results in a research agenda on work and ageing and in recommendations for practice. © 2009 Psychology Press. ispartof: European Journal of Work and Organizational Psychology vol:19 issue:1 pages:76-101 status: published
Imidazole derivative KK-42 reduces ecdysteroid titers and interferes with reproductive processes in adult females of Tenebrio molitor
2004
0048-3575 doi: DOI: 10.1016/j.pestbp.2004.07.004; KK-42, an imidazole derivative considered as potent inhibitor of ecdysteroid biosynthesis, was tested on adult females of Tenebrio molitor. The compound was applied topically (0.1, 1, 5, and 10 μg/insect) on 0- or 2-day-old adult females or added to the culture medium (1 and 10 μM) of ovaries. To test the effect of KK-42 on the reproduction capacity, ovaries were explanted from 2- and 4-day-old females corresponding, respectively, to follicles at the beginning and the end of vitellogenesis. KK-42 treatment reduced the fecundity and the longevity of females, and in addition, it delayed oviposition and affected growth and development of oocyte…
Regulation of the effects of CYP2E1-induced oxidative stress by JNK signaling
2014
The generation of excessive amounts of reactive oxygen species (ROS) leads to cellular oxidative stress that underlies a variety of forms of hepatocyte injury and death including that from alcohol. Although ROS can induce cell damage through direct effects on cellular macromolecules, the injurious effects of ROS are mediated largely through changes in signal transduction pathways such as the mitogen-activated protein kinase c-Jun N-terminal kinase (JNK). In response to alcohol, hepatocytes have increased levels of the enzyme cytochrome P450 2E1 (CYP2E1) which generates an oxidant stress that promotes the development of alcoholic steatosis and liver injury. These effects are mediated in larg…
Aldosterone synthase activity in the Y-1 adrenal cell line.
1995
The Y-1 adrenal cell line was shown to produce 20 alpha-dihydroaldosterone from deoxycorticosterone. This compound was identified by GC-MS by comparison with the previously synthesized reference compound. Two other 18-hydroxylated metabolites were identified as 11 beta,18-dihydroxy-20 alpha-dihydroprogesterone from endogenous cholesterol and 18-hydroxy-20 alpha-dihydro-11-dehydrocorticosterone from DOC. The conditions necessary for the synthesis of these compounds are culturing in 20% serum-supplemented medium and repeated incubations with the substrate. The production of 11 beta-hydroxylated steroids and that of 18-oxygenated steroids is stimulated differently by ACTH and angiotensin II su…
Bartholomaei Facii De rebus gestis ab Alphonso Primo neapolitanorum rege commentariorum libri decem
1562
Sign.: a4, b2, c-z4, aa-ss4, *4, a-o4, p2 Indexs. - Segona part. amb port. pròpia. - Reclams. - Capll. i altra orn. - Errors de pàg., passa de p. 12 a 17
Dietari del capellá d'Anfos el Magnànim
1932
Atribuït a: Melchor Miralles Índexs
Rank two aCM bundles on the del Pezzo fourfold of degree 6 and its general hyperplane section
2018
International audience; In the present paper we completely classify locally free sheaves of rank 2 with vanishing intermediate cohomology modules on the image of the Segre embedding $\mathbb{P}^2$ x $\mathbb{P}^2 \subseteq \mathbb{P}^8$ and its general hyperplane sections.Such a classification extends similar already known results regarding del Pezzo varieties with Picard numbers 1 and 3 and dimension at least 3.